Quality control charts are well-known process monitoring tools in the Statistical Process Control (SPC) that can be used to help control, predict, and improve the processes . The control charts are divided into two categories, namely, the memoryless and the memory-type charts. The memoryless control charts are called the Shewhart-type charts, which are sensitive against the large process shifts. On the other hand, the memory-type charts are frequently used in the process and service industries to detect small and moderate shifts in the process parameter(s) to avoid severe financial penalties that arise from these process shifts. Memory-type control charts include the cumulative sum (CUSUM) and the exponentially weighted moving average (EWMA) charts. When monitoring a production process, it is essential to detect all kinds of shifts in the process parameter(s).
